The government has drawn up a list of so-called "red line" issues detailing national security concerns of the proposed deal between BAE Systems and EADS.

The deal would create the world's biggest aerospace company with a market value of more than £30 billion and 220,000 staff.

Experts have raised concerns over the political hurdles the mega-merger faces, given the sensitive nature of national security work handled by the two firms and with approval required from a number of governments worldwide.

The British Government has a so-called golden share in BAE that allows it to veto deals that are seen to put the public interest at risk and has already said it will seek to ensure UK interests are "properly protected".

The Ministry of Defence (MoD) has told BAE Systems and proposed merger partner EADS they must provide safeguards over Britain's Trident nuclear weapons programme before the multi-billion-pound tie-up can go ahead, it was reported today.

Guarantees over Trident nuclear submarines - which are built by BAE at its yard in Barrow-in-Furness, Cumbria - are the top priority for the MoD and Department for Business, according to the Sunday Times.